Re: Firebird and PostgreSQL at the DB Corral.

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От Jeff Davis
Тема Re: Firebird and PostgreSQL at the DB Corral.
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Msg-id 1071965691.17017.97.camel@jeff
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Ответ на Re: Firebird and PostgreSQL at the DB Corral.  (Martijn van Oosterhout <kleptog@svana.org>)
Ответы Re: Firebird and PostgreSQL at the DB Corral.
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> >
> > What, exactly, is a partial index? A functional index is an index on
> > something like ((ColumnX*2)/14)? I think the functional one (is that
> > also an expression index?) is on the way.
>
> A partial index is a index on a subset of a table. The case I can think of
> is a list of transactions, some of which are yet to be billed. They have a
> BillID field which is NULL. since this is the recent set it is queried quite
> often, so you can build an index like:
>

Are NULLs even indexed?

    Jeff Davis




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